The present invention relates to a new and improved pipe inspection apparatus and, more specifically, to an apparatus for recording video images of a pipeline interior. Water pipelines including those pipelines disposed underwater need periodic maintenance. In order to determine whether periodic maintenance is required, the pipes must be inspected. If the pipes are large enough, a diver can manually inspect the pipes for signs of wear and tear or rupture. However, inspecting pipes in this manual way is costly in terms of labor costs and is dangerous. Further, many pipelines are too long to be inspected manually, i.e. either the pipes are too long for a diver to physically swim the length of pipe required or, a diver is unable to carry a sufficient amount of oxygen to swim the length of pipe required.
As a result, automated apparatuses have been developed for the inspection of pipes. In a typical design, an apparatus equipped with a camera is tethered to a motor-driven winch and is dragged along the length of the pipeline. Because typical winches include only 12,000 feet of line, the tethered devices are limited to pipelines of about 2 miles in length. Because some pipelines are several miles in length, conventional tethered devices cannot be utilized. In addition to tethered devices, motor driven devices have been provided but these devices are limited by their battery life and therefore the length of pipeline that can be inspected using these devices is also limited.
As an improvement to the tethered and motor-driven devices, apparatuses have been developed which are carried along the length of the pipeline by the flowing fluid. One example of such a device is found in U.S. Pat. No. 5,287,133. In the device shown in this patent, a buoyant vessel is provided which carries a video camera. A supporting leg is mounted to the vessel in an off-center position and a wheel mounted on a lower end of the leg, rolls along the bottom surface of the pipe. The problems with the device shown and described in U.S. Pat. No. 5,287,133 are twofold. First, the guiding leg engages the bottom of the pipeline which typically contains more debris than the top surface of the pipeline. Because the leg engages more debris, the vessel and camera are shaken more thereby resulting in a video picture of a reduced quality. Further, while the device illustrated in U.S. Pat. No. 5,287,133 does provide some shock absorbing quality between the supporting leg and the vessel, the shock absorbing capability is limited. Still further, it is difficult to adjust the orientation or angle of the vessel with respect to the pipeline.
Accordingly, there is a need for an improved apparatus for inspecting pipeline by way of recording images of the interior of the pipeline with a video camera which provides for improved stability of the apparatus and the camera and improved adjustability of the angle of the apparatus and camera with respect to the pipeline interior.